Large intestine Structure and FUnction

Question 1

illium - caecum valve name?

Answer 1

Ileo-cecal valve

Question 2

Vremiform is what?

Answer 2

appendix

Question 3

length of colon

Answer 3

1.5-1.8m

Question 4

Does the large intestine have villi? Why?

Answer 4

No, flat surface to move dehydrating poop out easier

Question 5

Does the large intestine have crypts/goblet cells?

Answer 5

Yes

Question 6

Why does the large intestine need a large amount of goblet cells?

Answer 6

High amounts of lubrication are needed

Question 7

Rectum mucosa? What is the muscularis externa like in the rectum?

Answer 7

Simpole columnar epithelium. Thick muscularis externa compared to other GI regions

Question 8

What is the thickenin of the muscularis of anal canal called? What other muscle is there?

Answer 8

Internal (smooth muscle) anal sphincter.

Also has external anal sphincter which is skeletal muscle (we control woo)

Question 9

What is the transition of epithelium in the anal canal?

Answer 9

simple columnar to stratified squamous

Question 10

How does the colon resorbed water?

Answer 10

THrough sodium resorption (initialted by the NaKATPase pump which osmotically brings water in

Question 11

Why do we want a long residensce time in colon? How many bact? What foes bacerial fermentation do?

Answer 11

Time for bact to act!

10^14 (1kg)

Ferments undigested carbs (cellulose) to short chain fatty acid.
Produces Vit K

Question 12

What key ntrient do the bact. of our larg intestine produce? What do we do for babies?

Answer 12

Vit K

Give babies an injection

Question 13

What gasses do we fart? CAused by what?

Answer 13

Methane, Nitrogen, CO2, Hydrogen, Hydrogen Sulphide

Question 14

Which anal sphincter do we have control over?

Answer 14

The external one

Question 15

What is the defaecation reflex? WHat is it stimulated by?

Answer 15

Our urge to poop.

Caused by mechanoreceptors in rectum sensing distension, and stimulated by increased peristaltic activity in the colon.

Question 16

What type of peristalis do we get following a meal?

Answer 16

Mass movement contraction (intense peristalsis) colon - rectum

Question 17

What controls the defaecation reflex?

Answer 17

Parasympathetic control – via pelvic splanchnic nerves (no sympathetic influence)

Question 18

What symptoms are associated with a constipation?

Answer 18

Headache, Nausea, loss of appitite, abdominal distension

Question 19

WHat is diarrhoea? WHat are the issues? WHat are the causes?

Answer 19

too runny and too frequent diahorrea

Dehydration is main issue

Can be caused by bact, vius, toxins, foodm stress, protozoa

Question 20

Vibrio Cholerae, E.Coli both produce what? WHat effect does this have?

Answer 20

Enterotoxigenic Bacteria

(So they both produce enterotoxins, which maximally turn on Cl secretion from crypt cells into the lumen)

Brings in a shed tonne of water

Question 21

Which intracellular second messengers will be elevated by exnterotoxigenic batheria?

Answer 21

cAMP, cGMP and calcium

Question 22

How is secretory Diarrhoea treated?

Answer 22

Oral rehydration treatment

Salt and Glucose, drives H20 reabsorption